(1) Field of the Invention
The present invention relates to a cyclone aerosol sampler mated with a chemiluminescent (CL) reagent injector and a biological aerosol CL detection system employing said cyclone aerosol sampler mated with said CL reagent injector. The interior surfaces of the cyclone aerosol sampler and the CL reagent injector employed are fabricated from materials that are free of metals that would initiate a CL-based reaction therein. The cyclone aerosol sampler employed serves as an aerosol sample collector as well as a CL reagent/sample mixing chamber. CL reagent is injected/introduced directly into the cyclone aerosol sampler during operation. Use of the sampler in a biological aerosol CL detection system provides a biological aerosol CL detection system having optimal sensitivity to the detection of biological materials in an aerosol sample. A method for detecting the presence of biological materials using the improved CL detection system herein is described.
(2) Description of the Related Art
Chemiluminescence (CL) has been used in the prior art for the detection and/or quantitative measurement of biological materials present in various types of samples. A CL technique taught by the prior art employs the use of a CL reagent such as luminol (5-amino-2,3-dihydro-1,4-phthalazinedione) in the presence of an oxygen donor reactant, such as hydrogen peroxide, which upon contact with biological materials produces detectable light via chemiluminescence. In operation, a collected sample is treated with a CL reagent that reacts with generic biological components present in the sample to produce detectable photons of light. These generic biological components initiate the CL-based reaction.
The principle of the luminol CL method for detecting bacteria is based on the following, well known, chemical reaction: ##EQU1## This CL reaction is proportional to the amount of biological material present in a test sample and is a sensitive means to identify biological material-containing samples. The luminol-based reaction is catalyzed by iron-containing macromolecules, such as hemins, which are ubiquitous to a wide variety of biological cells. Hemins include chemical materials, such as, Cytochrome C, microperoxidase, hemoglobins and the like. This chemical reaction, as set forth, serves as a means to rapidly detect and monitor the presence of and the amounts of materials of biological origin--i.e., those containing bacterial porphyrins.
Many CL detection systems are set forth in the prior art--Witz et al., U.S. Pat. No. 3,690,837; Witz et al., U.S. Pat. No. 3,754,868; Witz et al., U.S. Pat. No. 3,797,999; Soli, U.S. Pat. No. 3,567,586; Schiff et al., U.S. Pat. No. 4,765,961; Jeffers et al., U.S. Pat. No. 4,176,007; Chappelle et al., U.S. Pat. No. 4,385,113; and numerous others.
The use of a cyclone sampler for bioaerosols is taught in the prior art by Upton et al., "A Wind Tunnel Evaluation of the Physical Sampling Efficiencies of 3 Bioaerosol Samplers," J. Aerosol Sci., Vol. 25, No. 8, pp 1493-1501 (1994). Upton et al. teach a cyclone sampler, Aerojet General Glass Cyclone, for the collection of biological samples, where the biological samples are collected in solution. The sample solution collected via the cyclone sampler is presumably later subjected to treatment with an assay.
The use of a cyclone sampler in a cellular material detection apparatus is taught by Squirrell in U.S. Pat. No. 5,773,710 and U.S. Pat. No. 5,918,259. In the Squirrell patents, a particulate fraction from a gaseous environment (sample) is collected in a processing fluid via the use of a cyclone sampler. The collected sample solution is then later treated with a luminescent reagent downstream from the cyclone sampler in the apparatus. The material from which the cyclone sampler is fabricated is not identified.
The invention herein provides a detection system employing a cyclone aerosol sampler having inner surfaces fabricated from specific materials, wherein the aerosol sample collected therein is collected in a dried state; it is not collected in solution prior to it being subjected to a CL reagent. The dry aerosol sample is directly mixed with a CL reagent within the cyclone aerosol sampler. The invention provides for a detection system having increased sensitivity and an optimum signal-to-noise ratio.
There exists a continuing need to provide improved apparatus and methods for the detection of the presence of biological materials in various samples employing the well known CL assay system described. Specifically, it would be desirable to provide an apparatus for detecting the presence of biological materials in aerosol samples, wherein the apparatus has high sensitivity to the presence of biological materials. It is further desirable to provide a detection system having minimal baseline CL signals, and hence enhanced sensitivity. The present invention describes such a system, wherein the system provides a simple and accurate means for detecting the presence of biological agents in an aerosol sample.